Thread-controlling device for sewing-machines



2 SheetsSheet 1.

7 (Model.)

G WILLETT. THREAD CONTROLLING DEVICE FOR SEWING MACHINES. No. 245,905.

Patented Aug. 16,1881.

2 Sheets-Sheet 2.

(ModeL) G. WILLETT.

THREAD GONTROLLING DEVICE FOR SEWING MACHINES.

Patented Aug. I 16, 1881..

UNITED STATES PATENT QEEICE.

GEORGE WILLETT, OF CHICAGO, ILLINOIS.

THREAD-CONTROLLlNG DEVICE FOR SEWlNG-MACHINES.

SPECIFICATION forming part of Letters Patent No. 245,905, dated August 16, 1881.

(ModeL) To all whom it may concern Be it known that I, GEORGE WILLET'r, of Chicago, in the county ofUook, andin the State ofIllinois, have invented certain new and useful Improvements in 'lhread-Gontrollin g Devices for Sewing-Machines; and I do hereby declare that the following is afull, clear, and exact description thereof, reference being had to the accompanying drawings, making a part of this specification, in'which Figures 1 and 2 are side elevations of the head of the stationary arm of a sewingmachine having attached thereto n1 thread-controlling mechanism, and show, respectively, the positions of parts when the needle-bar is atthe highest and atthelowest limit of its motion. Figs. 3 and 4 are vertical central sections of said thread-controlling mechanism upon lines parallel with said stationary arm,

and show, respectively, the relative positions of parts shown in Figs. 1 and 2. Fig. 5 is a central longitudinal section of the plungertube separated from its connecting parts. Fig. 6is aperspective view of the lower end of the head from the rear, and shows the separable cap. Fig. 7 is a central longitudinal section of the plunger and its guide when arranged as a positive take-up. Fig. 8 is a rear elevation of the presser-bar, needle-bar, and tube for regulating the tension of the thread with relation to the thickness of the fabric being operated upon in the upward movement of the needlebar, the full lines showing the highest position ofsaid tube and the dotted lines its lowest position. Fig. 9 is a like view of the same, the vertical position of the regulating-tube being adjusted by a hand-lever, and Fig. 10 is a side elevation of saidparts.

Letters of like name and kind refer to like parts in each of the figures.

The design of my invention is to enable the thread to be drawn from the spool in proportion to the thickness of the goods under the presser-foot, thereby making the tension on the thread the same on thick or thin goods; and tothis end itconsists, principally, in the means employed for automatically varying the quantity of thread drawn from the spool in accordance with the vertical position of the presserfoot, thereby adapting the tension of the thread to the thickness of the goods being operated upon, substantially as and for the purpose hereinafter specified.

In consists,further,in a thread loop or guide connected with the needle-bar by means of an adjustable spring, and adapted to draw the thread over a relatively-fixed hearing as said substantially as and for the purpose hereinafter shown and described.

It consists, finally, in the combination of the thread-controlling and take-up mechanism, substantially as and for the purpose hereinafter specified.

In the annexed drawings, A represents the head or housing of the stationary arm B of a sewing-machine, within which head are contained a needle-bar, G, and a presser-bar, D, of usual construction. The head A in rear of the needle-bar G is cut away, except near its upper and lower ends, and within the latter is provided a round vertical opening, a, that receives and contains a tube, E, which is preferably constructed from wire wound spirally, and has its lower end projecting below said head. The upper end of the tube E is loosely connected with one end of a bar, F, which extends horizontally across the head A, is pivoted at or near its longitudinal center to or upon said head, and has its opposite end connected with the presser-bar D, the arrangement being such as to cause said tube to be raised by the downward movement of said presserbar, and to be moved downward as the latter is raised. For convenience in placing said parts in and removing the same from position, the rear side, at the lower end of said head A, is made separate like a cap, and is secured in place by means of a screw.

Secured upon and extending rearward from the central portion of the needle-bar O is an arm, 0, which is provided with a vertical threaded opening, 0, that coincides with the opening a and receives an eXteriorly-threaded tube, G, which has a length of about one and one-half inch. The tube G has an axial opening, g, which, from its lower end to or near the longitudinal center of said tube, has a diameter of about one-sixteenth of an inch, while from thence to the upper end of said tube said opening has a considerably larger diameter.

Within the tube G is fitted a rod, H, that loosely fills the lower portion of the opening 9, and is provided near its lower end with a collar, h, and has its upper portion threaded and provided with a nut, It. Around the upper portion of said rod, between said nut h and the bottom of the enlarged portion of the opening g, is placed a spiral spring, I, which operates to hold said rod H at the upper limit of its motion with a yielding pressure, that may be increased or diminished by turning said nut h downward or upward upon said rod. The lower end of the rod H is provided with athreadeye, h which is arranged for the passage of thread from the rear toward the front of the machine, and in order that said eye may maintain such position said rod is provided with a radial lug, k which fits loosely into a vertical slot, g, that is formed within one side of the tube G, said arrangement insuring the circumferential position of said rod without interferin g with its free vertical movement within said tube.

A thread-eye, K, secured to the lower end of the head A in rear of the tube E, a second thread-eye, L, secured to and projecting rearward from the rear side at the upper end of said head, and an eye, a, secured to and projecting rearward from the lower end of the needle-bar C, completes my improvement, the operation of which is as follows, viz The thread M, after leaving the tension, is passed downward through the eye L, forward through the eyes K and 71,2, and thence downward through the eye a to the needle. As the needle-bar G descends the rod or plunger H. moves simultaneously downward, its thread-eye k at the lower limit of such motion being upon a line with the thread-eye K. When the needle-bar 0 ascends the thread M is drawn by the rod or plunger H upward within the tube E, such movement of said thread being continued until its tension is greater than the force of the spring I, when said spring will yield and permit the arm 0 to continue its upward motion without further movement of said thread. The thread M, passing from the eye K to the eye h, and from the latter to the eye 0, is drawn across the lower end of the tube E at an angle which is lessened as said tube is raised and increased as said tube is lowered, and as the length of thread required to extend between said points increases in proportion to the departure from straight lines, it will be seen that when said tube is lowered an increase in the amount of thread drawn from the spool will result, while by raising said tube the opposite will be true.

As the-vertical position of the tube E governs the amount of thread drawn from the spool, and as the amount required is greater for thick goods than when thin goods are being operated upon, it will be seen that the connection of said tube with the presser-bar accomplishes the desired result, the elevation of said bar by placing beneath the footthick goods causing said tube to be automatically lowered, so as to increase the amount of thread drawn from the spool, while the lowering of the presser-bar, as lighter goods are operated upon, causes said tube to rise and lessens the amount of thread drawn from the spool, thereby causin g a perfectly uniform tension upon the thread at all times, whether thick or thin goods are being operated upon.

In order that the tube E may be adjusted vertically, when desired, without reference to the movements of the presser-foot, I journal a toothed pinion, f, within a suitable recess in the head A, adjacent to andin position to engage with the grooved periphery of said tube, and to the rearward projecting pivotal bearin g or journal of said pinion I attach a lever, f, by means of which said pinion may be rotated, a downward movement of the outer end of said lever causing said tube to beraised while by raising the outer end of said lever said tube will be lowered. When thus adjusted vertically the position of the tube E may be insured'by providing a toothed segment for engagement with the outer end of the lever f, or a pin may be passed through an opening in the end of the latter and have its inner end contained within one of a number of openings provided within the rear side of the head A. It, now, the upper end of the tube E is disconnected from the bar F, said tube will be left free to be moved by the pinion f and lever f and when adjusted will remain in position. When said tube E is connected with said bar F the vertical movements of the former will cause said lever f to change position, as shown by the dotted and full lines of Fig. 7.

By means of the nut h the resistance ofi'ered by the spring I to the downward movement of the plunger H may be increased or dimin= ished.

The screw-thread upon the exterior of the tube G enables the same to be easily adjusted to the necessary vertical position.

If it is desired to make the movement of the take-up positive, the nut h is screwed downward until the collar h is drawn firmly against -the lower end of the tube G, in which position there is no yielding in the upward pull of the take-up. When the take-upis thus used itis best to remove the spring I from within the tube G.

Having thus fully set forth the nature and merits of my invention, what I claim as new is- 1. As a means for controlling the amount of thread drawn from the spool, the tube E, arranged between the take-up device G H71. and the lower end of the needle-bar O, and connected with the presser-barD by means of the "in the manner and for the purpose specified.

2. The combination, with the needle-bar O and the bearing or tube E, fixed relatively to said needle-bar, of the plunger H, having the thread-guide h and means for yieldingly connecting said plunger with the needle-bar, substantially as and for the purpose shown.

3. The hereinbefore-described take-up, consisting of the tube Gr, fitted within and moving with the arm 0, and provided with the axial opening g, the plunger H, fitted within said opening and provided with the collar h, nut h, and thread-eye h", and the spring I, placed within said tube around said plunger, said parts being combined with each other, the needle-bar G, and with a station ary thread-eye, K, substantially as and for the purpose set forth.

4. In combination with the tube E and its housing A a, the pinion f and lever f, substantially as and for the purpose shown and described.

5. In combination with the tube E, the pivoted bar F, the head A, and the presser-bar D, substantially as and for the purpose specified.

6. The combination of the vertically-adjustable tube E, the spring-plunger H, the needleharG, and intermediate mechanism connecting said parts with each other and with the head A, substantially as and for the purpose shown.

In testimony that I claim the foregoing I have hereunto set my hand this 6th day ofJuly, 5 1880.

GEORGE WILLETT.

Witnesses:

HENRY L. PRENTIGE, J. H. STEVENS. 

